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arXiv 2412.09009cs.LGphysics.comp-ph
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用于学习初边值问题广义解的物理信息Transformer神经算子

A physics-informed transformer neural operator for learning generalized solutions of initial boundary value problems

Department of Computational and Data Sciences, Indian Institute of Science(计算与数据科学系,印度科学研究院)

Sumanth Kumar Boya, Deepak Subramani

AI总结:

本文提出物理信息Transformer神经算子PINTO,通过交叉注意力实现的迭代核积分单元,仅用物理损失即可泛化到新初边值条件,并在五类PDE上显著降低误差。

摘要:

初边值问题普遍出现在由非线性偏微分方程(PDE)支配的工程和自然系统应用中。算子学习是一个新兴领域,它通过使用神经网络学习无限维输入与输出函数空间之间的映射来求解这些方程。这些神经算子结合数据(观测或模拟)和PDE残差(物理损失)进行训练。现有神经方法的一个主要缺点是,当面对新的初始/边界条件时需要重新训练,并且训练必须依赖大量模拟数据。我们开发了一种物理信息Transformer神经算子(名为PINTO),它能够高效泛化到未见过的初始和边界条件,并在无模拟设置下仅使用物理损失进行训练。主要创新在于我们提出的新型迭代核积分算子单元,该单元通过交叉注意力实现,将PDE解的域点转换为具有初始/边界条件感知能力的表示向量,从而能够高效学习新场景下的解函数。PINTO架构被用于模拟工程应用中重要方程的解:平流方程、Burgers方程,以及稳态和非稳态Navier-Stokes方程(三种流动场景)。对于这五个测试案例,我们表明,在未见过的初始/边界条件这一具有挑战性的测试条件下,其相对误差仅为其他领先的物理信息算子学习方法的五分之一至三分之一。此外,我们的PINTO模型能够在训练配位点未包含的时间步上准确求解平流方程和Burgers方程。代码可在https://github.com/quest-lab-iisc/PINTO获取。

英文摘要:

Initial boundary value problems arise commonly in applications with engineering and natural systems governed by nonlinear partial differential equations (PDEs). Operator learning is an emerging field for solving these equations by using a neural network to learn a map between infinite dimensional input and output function spaces. These neural operators are trained using a combination of data (observations or simulations) and PDE-residuals (physics-loss). A major drawback of existing neural approaches is the requirement to retrain with new initial/boundary conditions, and the necessity for a large amount of simulation data for training. We develop a physics-informed transformer neural operator (named PINTO) that efficiently generalizes to unseen initial and boundary conditions, trained in a simulation-free setting using only physics loss. The main innovation lies in our new iterative kernel integral operator units, implemented using cross-attention, to transform the PDE solution's domain points into an initial/boundary condition-aware representation vector, enabling efficient learning of the solution function for new scenarios. The PINTO architecture is applied to simulate the solutions of important equations used in engineering applications: advection, Burgers, and steady and unsteady Navier-Stokes equations (three flow scenarios). For these five test cases, we show that the relative errors during testing under challenging conditions of unseen initial/boundary conditions are only one-fifth to one-third of other leading physics informed operator learning methods. Moreover, our PINTO model is able to accurately solve the advection and Burgers equations at time steps that are not included in the training collocation points. The code is available at https://github.com/quest-lab-iisc/PINTO

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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